Training tools including a hollow space filled with freely movable particles of solid material are known in the art. Such a training tool is known, for instance, from DE 36 09 363, in which a dumbbell is described with is provided with a ball-shaped hollow space. In one of the embodiments, this hollow space is partly filled with granular material, so that the total weight of the dumbbell and the position of the imaginary center of gravity can be set.
By training with such a dumbbell, muscles and connective tissue can be strengthened on the basis of repeated loading.
An object of the present invention is to provide a training tool which, during use, muscles are strengthened and connective tissue is subjected to extra mechanical loading during the effort of the muscle, more particularly the deeper connective tissue structures. To that end, according to the invention, the hollow space in the training tool is made of substantially elongate design.
By making the hollow space in the training tool of substantially elongate design, a tool has been obtained with which the user during acceleration and deceleration in the longitudinal direction thereof experiences a special effect. During acceleration and deceleration in the direction mentioned, a part of the amount of freely movable particles of solid material does not move relative to the holder, because these particles already rest against the end of the elongate hollow space that is oriented oppositely to the force exerted by the user. These particles, together with the holder, constitute ‘dead mass’, comparable to the weight of the granular material in the hollow space of the dumbbell, and for that reason directly exert a reaction force on the muscle tissue and the connective tissue envelope. The other part of the total amount of freely movable particles of solid material initially merely starts to shift in the elongate hollow space during acceleration and deceleration, which requires relatively little energy from the user. Thereupon, however, after a certain transit time, upon arrival of the particles at the respective end of the elongate hollow space, the particles are accelerated or decelerated still, so that all particles eventually move at the same speed as the holder. This leads to the above-mentioned special effect, viz. a delayed reaction force on the user, so that an extra mechanical load is exerted on muscles and connective tissue of the user, after the muscles have already been contracted. As a result, the muscles strengthen, and an adjustment in tensile strength and architecture of the connective tissue takes place. The extra mechanical reaction force is exerted not only on the muscle tissue and the connective tissue envelope thereof, as is the case with the direct reaction force of the ‘dead mass’, but also on the capsule/ligament apparatus of the joints, the connective tissue in and around the nerve, the connective tissue in the vascular walls, the menisci and the vertebral disks, as well as on the bony structures of the postural and musculoskeletal system, and more particularly the deeper connective tissue structures. Due to the fact that the particles do not all arrive at the respective end of the hollow space at the same time, the reaction force is somewhat spread over time, so that the additional loading is not exerted at one single moment, as is the case with the ‘dead mass’, but is built up in the course of a certain length of time and then decreases gradually again, and is described as “reactive impact”. The extra loading is thus more in the nature of a soft, resilient impulse than of a hard jolt with a short impact. What is thus achieved is that the tissue is not strained by the extra reaction force, thereby preventing the occurrence of injuries. The special effect of the extra loading arises both upon onset of the movement (the acceleration) and at the termination of the movement (the deceleration). By modifying the orientation of the elongate hollow space, the load on the connective tissue also varies.
Preferably, the holder comprises a tube, so that the training tool rests conveniently in the hand and has a simple geometry. Thus, a cost price advantage is obtained. The tube not only surrounds the hollow space, but also forms a handgrip for the user. However, the training tool can also be provided with an ergonomically shaped handgrip fitted around or on the tube. What is achieved by making the tube of cylindrical design is that the dynamics to which the amount of freely movable particles of solid material is subjected is one-dimensional and is not disturbed by structures deviating from the elongate pattern. By performing three-dimensional movements with the training tool, the user can train the connective tissue three-dimensionally in a focused manner.
The particles do not necessarily need to exhibit a predetermined structure, but may be of an irregular shape such as shard-shaped for instance, or granular or fragmentary, as is the case with slate chippings. The particles may also or alternatively be eccentric, e.g., having an eccentric center of gravity, as is also the case with slate chippings. By thus choosing an amount of freely movable particles of solid material having an irregular and/or eccentric shape, a training tool is obtained where the reaction force builds up and decreases even more gradually, i.e., when the reactive impact is more pronounced. When handling the training tool, the particles, due to their irregular (e.g., shard-shaped) shape, slide into each other when the movement is decelerated by the end caps. Upon sliding into each other, the particles, whilst rotating and tilting, end up in a position where the summed distance of the particles relative to the end caps is minimized. During this time period the particles transfer their kinetic energy at least not entirely to the holder, so that the reaction force is delayed. Moreover, at least a part of the kinetic energy is converted into heat. These two effects produce the reactive impact that counteracts the occurrence of a hard jolt with a short impact still further and reduce the chances of injuries being sustained. It is not required that all the particles have the irregular and/or eccentric shape, but that a sufficiently large percentage do provide a reactive impact. For example, if substantially all the particles are so configured, the reactive impact will result.
Preferably, the amount of freely movable particles of solid material make sound upon mutual collisions and/or upon collisions with the wall and/or an end face of the training tool, which is effected, for instance, by making the tube wall, the end face of the hollow space and/or the material of hard design, or by making the particles of solid material of non-hygroscopic design, so that the particles do not attract moisture. The sound gives the user, and possibly any bystanders, the sensation that a certain training intensity is being practiced. More particularly, the rhythmic handling of the training tool contributes to this aspect.
By coupling the training tool to another, similar training tool with the aid of a coupling piece, the user can adjust the weight that causes the reaction forces, more particularly set it to meet a specific need regarding his or her connective tissue to be stimulated.
By fastening the training tool to a limb, such as an arm, hand, leg or foot, optionally with the aid of an accessory, it is no longer necessary to grip the tool with the hand. In this way, the user can also stimulate the connective tissue of the lower limbs.
The invention further relates to a coupling piece.
The invention also relates to a method for handling a training tool.
Further advantageous embodiments of the invention are set forth in the dependent claims.